DOLICHOTHELE. 



6i 



12. DOLICHOTHELE (Schumann) gen. nov. 



Plant- body globose, more or less cespitose, soft in texture, never milky ; tubercles elongated, not 

 grooved above ; flowers borne in axils of old tubercles, very large, with a definite funnel-shaped tube ; 

 inner perianth-segments yellow, spatulate, tapering into a claw and borne on top of tube ; stamens 

 forming a spiral about style and borne on whole face of throat, but forming a definite ring at top of 

 throat; style slender; stigma-lobes linear; ovary exserted, naked; fruit smooth, greenish, purplish, or 

 red, globose, ellipsoid or short-oblong; seeds black or brownish. 



Type species : Mamniillaria longimamma De CandoUe. 



The generic name is from hoKi-xos long, and d-qXri nipple, referring to the elongated 

 tubercles. 



The fruit is not often collected and is not well known. Dr. Rose obtained a single 

 fruit of one of the species, the only one we had then seen, in a private collection in Rome in 

 191 5 ; this is nearly globular, red, thin-walled, many-seeded; the seeds are brownish, pitted, 

 slightly flattened, pointed at base, with a small sub-basal hilum. In October 192 1, Robert 

 Runyon sent us a number of fruits which were greenish white to purplish, with black seeds, 

 these somewhat flattened and pitted. 



Fig. 58. — Phellosperma tetrancistra. 



l''i<;. 59. — Dolichothele longimamma. 



Mammillaria camptotricha Dams (Gartenwelt 10: 14. 1905) is usually considered as a 

 close relative of this group, but it differs widely from it in the flowers as well as in other ways, 

 and we believe that it is not congeneric with it (see page 126). 



Three species, natives of southern Texas and northern and central Mexico, are 

 recognized. 



Key to Species. 



Spines glabrous, even when very young; species of Texas and northern Mexico i. D. sphaerica 



Spines puberulent; species of central Mexico. 



Tubercles very long (sometimes 5 cm. long), pale green, glaucous; radials 6 or more; 



central spines usually present 2. D. longimamma 



Tubercles much shorter, bright green; radial spines 4 or 5; central spines none 3. D. uberiformis 



1. Dolichothele sphaerica (Dietrich). 



Mammillaria sphaerica Dietrich in Poselger, Allg. Gartenz. 21: 94. 1853. 



Cactus sphaericus Kuntze, Rev. Gen. PI. i: 261. 1891. 



Mammillaria longimamma sphaerica K. Brandegee, Cycl. Amer. Hort. Bailey 2: 975. 1900. 



